In recent years, a collision avoidance apparatus has been proposed which detects obstacles around a driver's own vehicle, determines the possibility that the driver's own vehicle will collide with the obstacles, and performs collision avoidance when the collision possibility is high (for example, see JP-A-7-104062). The collision avoidance apparatus predicts the track of the obstacle around the driver's own vehicle, and notifies the driver of a collision risk or automatically decelerates the driver's own vehicle when the driver's own vehicle is likely to collide with the obstacle, thereby avoiding collision.